Brake testing apparatus



g 24, 1943- c. c. BENNETT 2,327,617

BRAKE TESTING APPARATUS Original Filed June l9, 1936 -2 Sheets-Sheet 1 INVENTOR.

/ 62 4005 CLSEA/NETT ATTORNEY.

1943. c. c. BENNETT 2,327,617

BRAKE TEST ING APPARATUS Original Filed June 19, 1936 2 Sheets-Sheet 2 I INVENTOR.

CLAUOE CBE/V/VL'TT A T TORNEY.

Patented Aug. 24, 1943 UNITED STATES rarest-1 TOFFICE u r 1 2,327,617 1 BRAKE TESTING APPARATUS Claude G. Bennett, South Bend, Ind, assignor to A. E. Feragen, Inc., Seattle, Wash, acorporation of Washington Continuation of application, Serial No. 86,123,

June 19, 1936. This application filed September 25, 1939. Serial No. 296,479

9 Claims- (Cl. 7e--51$ This inventionrelates to brake testing apparatus. Y

The instant application is a continuation of my co-pending application, SerialNo. 86,123, filed June 19, 1936, Automobile testing machines.

Broadly the invention comprehends an apparatus for testing the brakes of a motor vehicle wherein the resistance of the brakes isdetermined While the wheels of the vehicle are in motion as in actual use of the brakes in normal usage of the vehicle. V I

An object of the invention is to provide a brake testing apparatus for motor vehicle brakes of the dynamic type wherein actual roadconditions, particularly the inertia of the vehicle, are simulated.

Another object of the invention is to provide an improved means for supporting and rotating the front wheels of a motor against the resistance of their associated brakes. 7

Other objects and advantages of the-invention will appear from the following description taken in connection with the accompanying drawings forming a part of this specification, and in which v Fig. 1 is a top plan view of a brake testing ap paratus embodying the invention;

Fig. 2 is a view partly in elevation and partly in section illustrating a preferred construction of a wheel supporting roller; Y

Fig. 3' is a side elevation of a movable carriage;

wheel Fig. 4 is a top plan view of the carriage partly in horizontal cross section;

Fig. 5 is a sectional view taken substantially on line 5-5, Fig. 3; a m

Fig. 6 is a detail view of the dynamometer torque arm and cooperating parts; and

Fig. '7 is a sectional view taken substantiallyv frames are preferably elevated, and ramps 14.

and Hi are provided at the approachends there of. A pair of correspondingrunways l8 and 25 each including telescopic sections 22 and 2d are secured to theforward ends of the frames, and

corresponding movable carriages 26 and 28 support the forward ends of the runways. By adjusting the runways,:the overal1lengthof the machine may be increased or decreased to accommodate motor vehicles of varying wheel base.

A transverse shaft 38 is suitably journaled on the frames l8 and I2, andshafts 32 and 34 are journaled on the respective frames l0 and i2 in spaced parallel relation to the shaft A pair ofrollers 38 and 36 are secured to the shafts Si) and 32 respectively Within the frame it], and correspondingly a pair of rollers 42 and ll? are secured to the shafts 30 and 34 respectively within the frame l2. The respective pairs of rollers serve to suitably cradle the driving wheels of a motor vehicle.

A dynamometer case 64 mounted for oscillation on the shaft 36 between the frames ii] and I2 encloses a dynamometer (not shown) preferably of the type fully disclosed in my co-pending application, Serial No. 164,438, filed September 18, 1937. As shown, the dynamometer case i l has suitably secured thereto a torque arm 46 bearing on a slide 48 movable on an arm 59 pivoted on a plate 52s1idably mounted on a cross-member 5'3 connecting the frames H1 and i2. The free end of the arm 58 engages the actuator of a fluid pressure producing device 56 of any suit-, able type, and the fluid pressure-producing device is-' connected by, a fluid pressure delivery pipe or conduit 58 to an indicating instrument 6i) arranged on a suitable instrument board. The dynamometer case 44 has an air inlet SZand a Water supply system including inlets 6 5- and outlets 66, the latter preferably controlled by suitable valves $58 and W suitably arranged on the instrument board.

wheels are drivenby the power plant of the vehicle, and the rollers are driven by frictional engagement of the driving wheels therewith. Rotation of the rollers 38 and 42 and, accordingly, rotation of the 'shaft 30, activates the dynamometer so that the power derived from the power plant of the vehicle may be ascertained and the load thereon controlled.

The movable carriages Z6 and 28 each include a base T2 having thereona turntable it normally held against movement by a lockpin i6, and pivo'tally mounted on this turntableat T! is a frame lflnormally held against movement by a lockpin 88. A pairof spaced rollers 82 and M are journaled in the frame it, and a belt 3% connecting the rollers'is supported between the rollers by a plurality of relatively small rollers 88 arranged in spaced parallel relation to one another so as to inhibit sagging of the belt. While this structure is admirably adaptable for testing a. motor vehicle as to its steering geometry, it is equally desirable for the purpose of supportingthe front wheels of a vehicle, the brakes of which are to undergo test.

The front wheels of the vehicle rest upon the belts 86 and are driven by frictional engagement therewith in the same direction of rotation as that of the driving wheel of the vehicle. To this end the shafts 32 and 34 are extended, and beveled driving gears 90 sleeved on the extensions are adapted to mesh with beveled gears 92 on driving shafts 94 supported on the sides of the runways I8 and 20 and connected by'fiexible shafts 95 to the rollers 82. Clutch members 98 splined on the extended portions of the shafts 32 I and 34 cooperate with clutch members I on the driving gears 90 so that the drivin means for the belts 86 may be controlled asmay be desired or required during the test.

A preferred construction of the rollers 36' and 40 is illustrated in Fig. 2, and the same or a similar construction may be incorporated in one of the pulleys 82 or 8 1, It obvious that in'testing the brakes of a motor vehicle while it is stationary, unless there is some element tending to continue rotation of the wheels in the same manner as the inertia of the vehicle traveling along the road tends to continue the wheels in rotation, a true test of the braking action cannot be attained'. To simulate the inertia of a motor vehicle traveling at any given speed upon a roadway, it is proposed'to provide inertia means tending to continue rotation of the rollers supporting the wheels of thev'ehicle so that each wheel may be urged to continue its rotation during the testmg of the brakes associated With the wheels.

A preferred construction of the rollers to accomplish this end includes a hollow roller I02 keyed to a shaft Hi l. A mass I86 similar'to a flywheel having a clutch member I08 fixed thereto is mounted for rotation on the'shaft, preferably Within the roller. A clutch member Ill} splined to the shaft I64 so as to slide thereon and to rotate therewith cooperates with the clutch member I68 as hereinafter discussed. A cylinder I I Z'surrounding' the shaft has therein a plunger H4 also surrounding the shaft and cooperating with the slidable clutch member HQ; The cylinder H2 has connected thereto a fluid pressure delivery pipe or conduit IIfi' controlled by a valve H8". I a

With the clutch members I88 and III! engaged,

iestatic inertia of the mass associated with'each roller and with each wheel' of thev'ehicle simulates the inertia of the vehicle'in starting rotation of the driving wheels of the vehicle. As these commence to rotate, the fly wheel or mass is caused to rotate, and eventually achieves a speedcc-rrespondingto the speed of the driving wheels of the vehicle, which may correspond to any selective road speed. Each of the fly wheels now has acquired dynamic inertia, and if the brakes of the vehicle are applied, this" dynamic inertia resists stoppage of rotation of the wheels of the vehicle, and in this way corresponds to the inertia of the vehicle'traveling along the roadway to stoppage by its'brakes.

To indicate the force on a brake, the valve i it, which may be positioned'o'n the instrument board, is turned so that the conduit H ii-is placedin'communication with a fluid pressure delivery pipe or conduit I29 connected to asuitable indicating instrument I22, also located on the instrument board. A separate valve I18 and indicating in strum'ent I22 for eachwheel' of the'v'ehiclemay be. placed on the instrument board. When the" power applied to drive the'rolls' is disconnected and the vehicle brakes are applied, the fly wheel or mas I06 tends to continue its rotation, while the vehicle brake tends to stop rotation of the to the brake indicating instrument I22. By suitable calibrations of the instrument, the distance within which the vehicle would have been stopped, or the brake effort required to effect that stop, may bedetermined.

The valve I I'8'may be manipulated to selectively place the conduit H6 in communication with a conduit I24 connected to a suitable source of pressure for actuating the clutch member III) into engagement with the clutch member I08Ior to interconnect the conduit I IS with a relief con duit I26 to relieve pressure and permit the clutch members to move'ap'art, q

In a brake testing operation, each of the brake indicating mechanisms may be" operated Separately or concomitantly, Thus, an operator may have before him comprehensive indications as to the condition of the individual-brakes, and as to the equalization ofthe'brake under a given'operating condition. I v p g V While this invention hasbeen described in connection with certain specific embodiments, the

principle involved is susceptible of numerous other applications that will readily occur to per sons skilled in the art, The invention is, there fore, to be limited only asindicated by the scope of the appendedclaims v V Having thus describedt-he variousfeatures of theinvention, what I claimas new and desireto secure by Letters Patent'is'- 1. A machine 'fortestirig the brakes on the. front wheels of a vehicle comprising a base, a wheel supporting member, means supporting the ='latter from 'the' base for rotative movement about a vertical axis for; movement transversely of the vehicle rnoveinent longitudinally of the vehicle, driven eans to support the driving' wheels of the vehicle, and power means driven by said driven-rneansto effect such longi-'-' tudinal movement of the wheel supporting member thereby tending to rotate the wheel oniits spindle in opposition'to" any braking action upon the Wheel. v

2. A machine for testing automobile brakes comprising a base, a belt extending longitudin'ally of the automobileand adapted for supporting engagement beneath the steerable front wheel of an automobile, a pair of rollers about which said belt extends, a frame supporting said rollers, supporting means interposed between said frame and said base for rotative movement of the frame abouta vertical axiswintermedia'te the ends of the belt and for swinging movement about another vertical axis adjacent the rear end of the belt, driven means to support the driving wheels of the automobile, and means and rollei's'f'r'om the driven to drive said beltmeans.

3. A machine for testing the brakes of the steerable wheels of vehicles comprising a' base and a wheel supporting member mounted thereon, an interposed member constraining the wheel supporting member to rotative movement about a iven vertical axis, another interposed member constraining the wheel supporting member to lateral swinging movement about a different vertical axis, and means driven by the driving wheels of the vehicle to move the wheel supporting member lengthwise to the vehicle to rotate the wheel as the wheel is swung on its king pin.

4. A brake tester comprising a shaft, a wheel supporting cylinder carried by the shaft, an inertia mass rotatably mounted on the shaft, cooperating clutch means having engaged and disengaged positions carried by the shaft and mass, yielding means to urge the clutch means toward the engaged position, and mean to indicate a force urging the clutch means toward the disengaged position upon relative movement between the clutch means carried by the shaft and mass due to application of the brakes.

5. A brake tester comprising a shaft, a vehicle wheel supporting cylinder fixed to the shaft, an inertia mass rotatably mounted on the shaft, cooperating one-Way drive and clutch means having engaged and disengaged positions carried by the shaft and mass whereby when the clutch means are engaged the vehicle wheel may drive the cylinder and mass, yielding means urging the clutch means toward the engaged position, and 7 means to indicate a force urging the clutch means toward the disengaged position when the inertia mass tends to rotate faster than the shaft.

6. A wheel supporting member for a brake tester comprising a shaft, a shell fixed to the shaft for supporting a wheel, a mass rotatable on the shaft independent of the shell, a clutch member having cam elements on the mass, a clutch member carried by the shaft and having cam elements cooperating with the cam elements of the clutch member on the mass, means yieldingly engaging said cam elements of the clutch members with each other, and means for measuring the force developed due to the tendency of the clutch members to disengage because of relative movement between the mass and the shell upon application of brakes.

7. A wheel supporting member for a brake tester comprising a shaft, a shell fixed to the shaft, a mass rotatable on the shaft within the shell, a clutch member on the mass, an axially movable clutch member on the shaft cooperating with the clutch member on the mass, fluid pressure actuated means for urging the axially movable clutch member into engagement with the clutch member on the mass, and means for measuring the force developed by movement of the clutchmember axially on the shaft relative to the clutch member on the mass uponrelative movement between the shaft and mass by application of brakes.

8. A wheel supporting member for a brake tester comprising a shaft, a shell fixed to the shaft, an inertia mass rotatable on the shaft,

a clutch element secured to the inertia mass, a

clutch element splined to the shaft and having .cam projections for cooperation with the clutch element on the inertia mass, means for engaging and yieldingly resisting disengagement of the clutch elements with each other, and means to measure the force required to overcome the yielding resistance to disengagement of the clutch elements caused by relative movement of the shaft and mass when the brake is applied.

9. A machine for testing the brakes on the steerable wheels of a motor vehicle having a base, wheel supporting means comprising a shaft having a horizontally extending axis and a cylinder fixed to the shaft for supporting a wheel, a mass rotatable on the shaft independent of the cylinder, means interposed between the wheel supporting means and the base whereby the wheel supporting means may move about a substantially vertical axis for movement transversely of the vehicle, power means to move the wheel supporting means about said horizontal axis to rotate the wheel in opposition to a braking force exerted thereon, cooperating clutch members carried by the shaft and mass, yielding means urging the clutch members toward engaging position relative to each other, and means for measuring the force urging the clutch members out of engaging position as the shaft and mass move relatively to each other upon application of brakes.

CLAUDE C. BENNETT.

I CERTIFICATE OF CORRECTION. Patent No. 2,527,617. August 21;, 19m.

CLAUDE C BENNETT.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5 first column, line 15, claimh ifor "mean" read --means--; and that the said Let- 1561' Patent should be. read with this correction therein that the same may confom to the record of the case in the Patent Office.

Signed aha sealed this 18th day of January, A'. D. 191m.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

